1. Field of the Invention
This invention relates to novel clay compositions useful as animal litters which assist in the diagnosis of animal health problems, to processes for making such compositions and to litters using such compositions.
2. Description of Related Art
Animal litters have been known for many years. They are employed to absorb animal urine and to disperse animal feces until the litter is either cleaned or disposed of.
In the home and veterinary hospital, litters are frequently employed for cats, small dogs, guinea pigs, rabbits, mice, gerbils, etc. It is neither desirable nor economical to constantly dispose of litter when it becomes contaminated with the animal urine or feces which it is meant to contain. Rather, the feces is scooped from the litter employing a litter sieving spoon.
The sieving-cleaning operation is more effective if the litter when contacted by the urine absorbs the urine and forms a deposit or clump of sufficient size and strength to be removed by the sieving-spoon along with the feces.
It is also desirable to include other materials such as bactericides, ammonia binding agents, extenders for such agents and pH indicators.
The addition of pH indicators is particularly useful for a variety of purposes such as to indicate the necessity of removing soiled litter and to provide by the indicated colors of the areas wetted by animal urine information about the health of the animal using the litter. For example, U.S. Pat. No. 5,143,023 which describes a litter for the accumulation of animal urine, such as domestic and cat litter, having at least one visual indicator chemically bound to the litter base material and a method for making such a litter. This patent describes the litter as having the chemical indicator chemically absorbed thereon, rather than merely physically absorbed, permitting the litter to be used as an effective mechanism by animal owners to determine potential health problems with their animals and the same litter may also serve as a useful diagnostic tool in a subsequent visit to a veterinarian. The litter base material is described as having the ability to exchange ions. Compounds to facilitate the agglomeration or clumping of the litter when contacting urine may also be added to litter base material.
There is still need, however, for improved litters having stronger and sharper color indications over the desired pH range, stronger color and sharper contrast as compared to clay substrate, improved color stability and effective agglomeration or clumping. It is also desirable that the initial color of a soiled litter be capable of reconstitution after the initial color has faded. It is, therefore, the purpose of the invention described herein to provide improved animal litters with such desired properties.